A standard flush toilet has a housing in which is set a bowl that is unitarily formed with a trap outlet. A nozzle ring is provided around the upwardly open mouth of the bowl to direct a plurality of streams of water straight down into the bowl. The incoming water causes the outlet to overflow and the resultant draining action, often augmented by a siphon effect, empties the bowl.
The nozzle ring is typically built into the cover or top part of the toilet and comprises an annular manifold passage fed at one location with water under pressure and having a plurality of outlets forming the nozzles. The nozzles furthest from the feed location are not in this system highly effective because they get little pressure, while those close to the feed location emit relatively powerful streams.